AQA computing

  AQA specification
http://web.aqa.org.uk/qual/gce/ict/computing_materials.php?id=04&prev=04

AQA will support the following programming languages.

• Pascal

 

This list will be updated as required. Centres will be asked to make their preferences known to AQA at the start of

the course.

3.1.1 Fundamentals of Problem Solving

Introduction to Principles Focus on studying the processes of computation and understanding

of Computation why and where they are important in Computing.

(See the

Stages of Problem Solving Understand the problem.

Define the problem

 given(s)
 
, goal,
ownership,
 resources
algorithm. See Chapter 1.2 ‘AQA Computing AS’ by Kevin Bond and Sylvia Langfield, published by Nelson Thornes

6

GCE Computing Specification for AS exams 2009 onwards and A2 exams 2010 onwards (version 1.5)

3

3.1.2 Fundamentals of Programming

Features of Imperative High Illustrate these features for a particular imperative, third-generation

Level Languages language such as Pascal.

Data Types Use the following appropriately.

• Built-in Integer, byte, real, boolean, character, string, date/time.

• User-defined Enumerated, subrange, sets, records, arrays.

The Role of Variables Recognise the different roles a variable can take:

fixed value, stepper, most recent holder, most wanted holder,

gatherer, transformation, follower, temporary.

Programming Statements Use these statement types.

• Type Definitions

• Variable Declarations

• Constant Definitions

• Procedure/Function

Declarations

• Assignment

• Iteration

• Selection

• Procedure and Function calling Explain the advantages of procedure/functions.

Arithmetic operators including +, –, /, x, DIV, MOD

modular arithmetic

Relational operators =, <, >, <>, <=, >=

Boolean operators NOT, AND, OR

Logical bitwise operators NOT, AND, OR, XOR

Set operators Union, difference, intersection, membership.

Built-in functions Arithmetic functions: round, truncation.

String handling functions: length, position, substring, concatenation.

String conversion functions to/from integer, real, date/time.

Constants and Variables Explain the advantages of named variables and constants.

Procedure and Function Describe the use of parameters to pass data within programs.

Parameters Understand the different mechanisms for parameter passing:

by value and by reference.

Fundamentals of Structured Understand the structured approach to program design and

Programming construction.

Construct and use structure tables, structure charts and hierarchy

charts when designing programs.

Use meaningful identifier names.

Use procedures/functions with interfaces.

Use procedures that execute a single task.

Explain the advantages of the structured approach.

Data Structures

• One- and Two-Dimensional Arrays Use arrays in the design of solutions to simple problems.

• Fields, Records and Files Read/write records from/to a file: csv file or file of records.

Validation Understand the importance of validation of input data.

Program simple validation.

7

GCE Computing Specification for AS exams 2009 onwards and A2 exams 2010 onwards (version 1.5)

3

3.1.3 Fundamentals of Data Representation

Bit Patterns in a Computer Explain the different interpretations that may be associated with a

pattern of bits.

Binary number system

Pure Binary Representation of Describe the representation of unsigned denary integers in binary.

Denary Integers Perform conversion from denary to binary and vice-versa.

Binary Arithmetic Add two binary numbers and multiply two binary numbers.

Representation of signed integers by Describe the use of Two’s Complement to perform subtraction.

Two’s Complement Convert a denary integer into Two’s Complement and vice versa.

The Concept of Number Bases: Describe the conversion of a denary integer to hexadecimal form and

Denary, Binary and Hexadecimal vice versa. Describe the use of hexadecimal as shorthand for binary.

Integers and Numbers with a Draw a distinction between integers and numbers with a fractional

Fractional Part part in a computer context.

Describe how an unsigned denary number with a fractional part is

represented in fixed-point form in binary.

Information Coding Schemes Describe standard coding systems for coding character data.

• ASCII Differentiate between the character code representation of a denary

• Unicode digit and its pure binary representation.

Error checking and correction Parity bits, Hamming code.

Gray coding Describe Gray coding. Explain why and where it is used.

Representing Images, Sound Describe how bit patterns may represent other forms of data

and other data including graphics and sound.

Bitmapped Graphics Bitmaps: resolution, colour depth and simple bitmap file calculations.

Vector Graphics Vector graphics: drawing list – objects and their properties.

Compare bitmaps to vector graphics; advantages, disadvantages.

Sound files The need for compression and basic techniques for compression.

Sampled Sound and Nyquist-theorem Sampling resolution, sampling rate.

Sound Synthesis Streaming audio.

Analogue and Digital Data Differentiate between analogue and digital data and analogue and

Analogue and Digital Signals digital signals.

Analogue to Digital Converter (ADC) Describe the principles of operation of an analogue to digital

converter.

3.1.4 Systems Development Life Cycle

Analysis Describe the stages of development of a hardware/software system.

Design Specify the method of testing the programmed solution (dry run

Implementation testing, black box testing, white box testing).

Testing Specify the selection of test data including normal (typical), boundary

and erroneous data.

Program the solution as per design.

Test the solution using selected test data.

Evaluation Reflect on how successful the operational system is.

8

GCE Computing Specification for AS exams 2009 onwards and A2 exams 2010 onwards (version 1.5

1

ISBN 978-0-7487-8298-7

constraints

Given(s) = the initial situation

Goal = Desired target situation

Ownership = who does what

Resources and constraints = tools, knowledge,

skills, materials and rules, regulations, guidelines,

boundaries, timings

Define boundaries.

Plan solution.

Check solution.

Top-down Design / Step-wise Consider sub-problems and the use of modules.

Refinement

Decision tables Determine logical conditions and consequential actions.

Finite state machines with outputs Mealy machine

Finite state machines without outputs Finite State Automation

• state transition diagrams Draw and interpret simple state transition diagrams, transition tables.

• state transition tables

Algorithm Design Understand the term

Express the solution to a simple problem as an algorithm using

flowcharts, pseudo-code or structured English and the standard

constructs:

• sequence

• assignment

• selection

• repetition.

Hand trace simple algorithms.

Convert a simple algorithm from

• structured English into pseudo-code,

• pseudo-code into high level program code.

Understand the standard algorithms: Bubble Sort, Linear Search.

Teacher Resource Bank for examples.)1:

3.1 Unit 1 COMP1 Problem Solving, Programming,

Data Representation and Practical Exercise